Shell manufacturing apparatus



Dec. 6, 1955 DQUGLASS 2,725,597

SHELL MANUFACTURING APPARATUS Filed NOV. 22, 1954 INVENTOR I 7 JOHN J. DOUGLASS BY ALQLAW ORNEY United States PatentO SHELL MANUFACTURING APPARATUS John J. Douglass, Pitman, N. J., assignor to E. I. du Pont de Nemours and Company, Wilmington, Del., a cop poration of Delaware The present invention pertains to a mechanism for turning back a protruding cylindrical liner about the end lip of a surrounding cylindrical encasement. More particularly, this invention relates to an apparatus for turning back a plastic or other flexible liner about the lip of a shell or other tube.

There are numerous instances in the diverse industrial arts where it is necessary to line a cylinder or tube'j-like member with a flexible liner. For example, such a liner may be needed for water-proofing purposes, or it may be needed to prevent leakage of a liquid from within a container. In such instances, the liner may be conveniently formed of rubber, polyethylene, or other plastic film.

In co-pending application Serial No. 354,840, filed May 13, 1953, in the name of Cyril James Breza, having a common assignee with the present application, there is described a shell used in the manufacture of explosive cartridges which comprises a rigid tubular outer casing, a tubular liner of a water-impervious flexible material within the casing, and a metal cap at each end of the lined casing. In order to affix the metal caps, it is first necessarythat the protruding ends of the flexible liner be turned back tightly and evenly over the edges of the casing. Otherwise the metal caps cannot properly grip the edges to form a unitary water-tight closure.

Accordingly, an object of the present invention is to provide an apparatus for turning back evenly and tightly the protruding ends of a flexible tubular liner about the edges of the rigid encasement which it lines. A further object is to provide an apparatus capable of performing such an operation as one step of a mechanized production process. A still further object is to provide an apparatus of the type described which will perform its function rapidly and efliciently. Other and additional objects will become apparent as the invention is further described.

To achieve a more complete understanding of the invention, reference is now made to the accompanying drawings depicting one specific embodiment thereof. In the drawings, Figure 1 represents a sectional view of the apparatus at the start of the operation cycle and Figure 2 represents a view of a portion of the apparatus at a point when the turn-over of the liner has just been completed but the shell or casing has not yet been released. Like numerals designate identical parts throughout the several views.

Referring now to the figures in greater detail, 1 represents a main support frame which may be a separate stanchion or it may be a wall of an adjacent piece of ma chinery. Fluid motor 3 is mounted in the outer end of a support bracket 2 which is affixed to the main frame. A shaft 7 is connected to the piston 6 of the fluid motor and carries a second fluid motor 8 at its other end. The base of the latter motor is integral with a hollow shaft 9 which passes through a cylindrical housing supported on main frame 1 by the bracket 4. An upper press member 12 is afiixed to the lower end of shaft 9. Passing through the press 12 and the hollow shaft 9, is a shaft 11 which is connected at its upper end to piston in the fluid motor 8 2,725,597 Patented Dec. 6, 1955 and which carries at its lower end the lower press member 13. A tubular ring-like expander 14 is positioned between the upper and lower presses and has a normal circumference slightly smaller than the inner circumference of the casings on which the apparatus will operate. The expander is formed of a resilient compressible material and may be made hollow as illustrated in the drawings for reasons which will hereinafter be manifest. The two presses 12 and 13 and the expander 14 comprise the operating head. A flexible-liner guide 15 is connected at one end of the housing 5 and at its other end to the lower press member 13. The cylindrical casing 16 containing the flexible liner 17 may be hand fed into the apparatus or. may be brought into positionby a movable rack or conveyor or other suitable means.

The operation of the apparatus is as follows: a tubular casing having a flexible liner protruding from one or more of its ends is positioned below and centrally of the housing 5 by any suitable means. Fluid motor 3 is actuated to lower piston 6 which in turn will lower the entire assembly 7, 8, 9, 12, 13 in juxtaposition. Press members 12 and 13 will be inserted into the confines of the lined casing 16. Fluid motor 8 is then actuated to raise piston 10 and shaft 11 and lower press member 13 connected therewith. As the lower press member 13 moves upwardly, it will act to compress and flatten expander 14 between the two presses 12 and 13. This flattening action of the expander will increase its outer circumference and thus press the liner guide 15 against the liner I7 and the casing 16. The fluid motor 3 is again actuated, this time to elevate piston 6 and the assembly connected thereto. As presses 12 and 13 and the flattened expander 14 therebetween rise, the flexible liner guide prescribes an ascending are within the housing 5. Casing 16 and its liner 17 are drawn upwardly with the presses 12 and 13 due to their frictional engagement therewith under the action of flattened expander 14. The upper protruding edge of'liner 17 is turned over the edge of casing 16 by the arc of the guide 15 when the edge of the casing approachesjsaid arc. The latter position during the operative cycle of the apparatus is most clearly illustrated in Figure 2. At this point, the upward travel of piston 6 in fluid motor 3 is halted and fluid motor 8 is again actuated, this time to lower piston 10. This releases the resilient expander 14 which then contracts back into its original shape. The resultant reduction of the outer circumference of the expander releases the casing and its liner which may then be carried away manually or automatically. The apparatus is in position to repeat its cycle on the next casing or on the remote end of the same casing and liner.

The liner guide 15 may be in the form of a single 360 flexible sheet, as illustratedjor it may be in the form of a number of separate strips The only requirement is that the material be substantial but flexible enough to produce the ascending arc during the operation of the apparatus. Such flexible materials as leather, rubber and plastic compositions are very suitable.

The ring-like expander is. preferably formed of rubber or plastic though any resilient, material which will not readily lose its resiliency is suitable. The expander may be solid or it may be hollow, depending upon the material selected and upon the specific dimensions involved.

Many variations and modifications of the apparatus depicted in the drawings will readily occur to one skilled in the art. The fluid motors 3 and 8 may be hydraulic or pneumatic or they may be replaced by any suitable mechanical power means such as cranks or racks and pinions. The construction of the press assembly can be widely varied by the substitution of pneumatically or hydraulically expandable units or mechanically expandable units for the compression-expandable expander 14. The housing 5 may be of any suitable configuration. The device may be operated vertically, as illustrated, horizontally, or at any convenient angle in between. Such variations and modifications do not depart from the scope of the present invention.

Having thus described my invention, I intend to be limited only by the following claims.

I claim:

, 1. A device for turning back a protruding cylindrical liner about the end lip of a surrounding cylindrical encasement comprising a support means, an. expansiblehead member mounted for linear reciprocation. on said support means, a flexible guide element interconnecting sail head member and said support means, and motive means for lowering said head into said lined cylindrical encasement, expanding said head, and elevating said head and encase merit in unison whereby said guide element will turnthe protruding portion of the liner over and about the said lip of the encasement. V

2. A device as in claim 1 wherein said head member comprises a pair of opposing presses and a ring-like expander of resilient material between said presses adjacent the outer peripheries thereof, said expander increasing its outer circumference when compressed by said presses.

3. A device as in claim 2 wherein said ring-like expander is hollow.

4. A device as in claim 1 wherein said guide element is a flexible arcuate member which contacts the protruding liner as it ascends in unison with the head member and ithe cylindrical encasement and turns it back over the lip of the encasement.

5. A device for turning a protruding cylindrical liner about the end lip of a surrounding cylindrical encasement comprising support means, an expansible head member mounted for linear reciprocation on said support means, primary motive means for reciprocating said head member into and out of the aforesaid cylindrical encasement, a flexible arcuate guide element adjustably interconnecting said head and said support means, said head member including a pair of presses and a hollow ring-like, resilient expander therebetween, and a secondary motive means to bring said presses together compressing the expander and thus increasing its outer circumference to frictionally engage the cylindrical encasement whereby the liner and its surrounding encasement will be moved in unison with said head and the protruding liner will be turned over and about the lip of the encasement under the action of the arcuate guide.

6. A device as in claim 5 wherein said primary and secondary motive means are fluid motors.

References Cited in the file of this patent UNITED STATES PATENTS Emmer July 9, 1946 2,485,885 Hoopes Oct. 25, 1949 

1. A DEVICE FOR TURNING BACK A PROTRUDING CYLINDRICAL LINER ABOUT THE END LIP OF A SURROUNDING CYLINDRICAL ENCASEMENT COMPRISING A SUPPORT MEANS, AN EXPANSIBLE HEAD MEMBER MOUNTED FOR LINEAR RECIPROCATION ON SAID SUPPORT MEANS, A FLEXIBLE GUIDE ELEMENT INTERCONNECTING SAID HEAD MEMBER AND SAID SUPPORT MEANS, AND MOTIVE MEANS FOR LOWERING SAID HEAD INTO SAID LINED CYLINDRICAL ENCASEMENT, EXPANDING SAID HEAD, AND ELEVATING SAID HEAD AND ENCASEMENT IN UNISON WHEREBY SAID GUIDE ELEMENT WILL TURN THE PROTRUDING PORTION OF THE LINEAR OVER AND ABOUT THE SAID LIP OF THE ENCASEMENT. 